1. Field of the Invention
The present invention relates to an image pickup device including focus detection pixels, and a focus detection apparatus including the image pickup device.
2. Description of the Related Art
In recent years, to detect a phase difference occurring depending on a deviation from a focus position, development of an image pickup device including focus detection pixels that have been pupil-divided has been put to practical use and commercialized. Such an image pickup device includes one described in Japanese Patent Application Laid-Open Publication No. 2009-60597, for example.
In an image pickup device currently put to practical use, a relatively small number of focus detection pixels are only arranged in a relatively narrow specific range within its screen, and an arrangement ratio (density) of the focus detection pixels is approximately 0.5%, for example.
On the other hand, to enhance focus detection performance, a large number of focus detection pixels are desirably arranged at a higher density (or further in a wider range).